This disclosure relates to a gas turbine engine, and more particularly to an impeller used in a high pressure turbine section to increase the pressure of a cooling fluid.
Gas turbine engines typically include a compressor section, a combustor section and a turbine section. During operation, air is pressurized in the compressor section and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases are communicated through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads.
Both the compressor and turbine sections may include alternating series of rotating blades and stationary vanes that extend into the core flow path of the gas turbine engine. For example, in the turbine section, turbine blades rotate and extract energy from the hot combustion gases that are communicated along the core flow path of the gas turbine engine. The turbine vanes, which generally do not rotate, guide the airflow and prepare it for the next set of blades.
Typically bleed air from a compressor stage is used to cool the turbine blades in the turbine section. The cooling fluid is routed to the turbine blades by a variety of structures and then fed to internal cooling passages in the blade through a space in a rotor slot within which the turbine blade's root is mounted. Sufficiently high pressures must be provided to ensure desired flow through the cooling passages to achieve desired cooling.